In a special “Rivers in Crisis” issue of Nature
, the lead article, “Global Threats to Human Water Security and River Biodiversity
,” presents damning evidence that manipulation of river systems — through the construction of canals, levees, hydroelectric projects, and other infrastructure — has caused serious and lasting biological damage to watersheds throughout both the developing and developed worlds. The authors (all 11 of them!) report that key rivers have become shadows of their former selves in terms of the amount of aquatic life they can support. Without drastically improved stewardship of waterways, “we are pushing these river systems toward catastrophe,” warns Peter McIntyre
, an article co-author.
The human impact on the world’s river systems will be hard to reverse, says Margaret Palmer, author of a second Nature article on freshwater biodiversity loss, “Beyond Infrastructure.” Human-induced changes to watersheds affect local hydrology at a fundamental level, she contends, weakening rivers’ ability to deliver crucial “ecological goods and services” — such as clean water and nutrient-rich sediment loads — that help maintain the health of local environments and the human populations that depend on them. To fully understand the scope of the problem, Palmer says more research is needed to explore the linkages between biodiversity levels and “ecosystem services” that healthy rivers provide.